Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations only declare readOnlyHint=false, idempotentHint=false and destructiveHint=false. The description adds substantive context annotations cannot express: the required content:write scope, that the first call performs no change, that unknown fields are refused by name, and that the preview returns a summary and confirm_token for human approval.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Short and front-loaded: permission requirement, then call count, then the sequencing. The opening sentence repeats the title and adds no information, which is the only waste.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description usefully characterizes what the first call returns (summary, confirm_token), which is what an agent most needs here. It omits what the confirming call returns and any constraints on acceptable domain values, leaving modest gaps.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is only 50%, and the one undocumented parameter is the required 'domain' – the description never states its expected format (bare hostname vs URL, wildcards, subdomain rules). The confirm_token explanation it does give duplicates the schema's own description.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ('Allow a domain for my widgets'), which an agent can distinguish from siblings like list_widget_domains and remove_widget_domain by implication. It does not name those siblings explicitly, and the first sentence largely restates the title, so it falls short of full differentiation.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Gives a clear procedure: call once to preview, show the summary to the person, then call again with the same arguments plus confirm_token. That is strong when-to-use guidance for this tool, but it never says when not to use it or points to the related list/remove siblings.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.